Re: [PATCH 1/8] remove flush_write_buffers() indma-mapping-common.h

From: FUJITA Tomonori
Date: Tue Aug 04 2009 - 21:50:26 EST


On Mon, 13 Jul 2009 15:25:53 +0900
FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx> wrote:

> From: Arnd Bergmann <arnd@xxxxxxxx>
>
> This moves flush_write_buffers() in asm-generic/dma-mapping-common.h to
> arch/x86/kernel/pci-nommu.c.
>
> The purpose of this patch is that, we can avoid defining NULL
> flush_write_buffers() on IA64 and SPARC.
>
> dma-mapping-common.h is used by X86 and IA64 (and SPARC soon) but only
> X86 with CONFIG_X86_OOSTORE or CONFIG_X86_PPRO_FENCE actually uses
> flush_write_buffers(). CONFIG_X86_OOSTORE or CONFIG_X86_PPRO_FENCE is
> usable with only kernel/pci-nommu.c (that is, not usable with other
> X86 IOMMU implementations such as SWIOTLB, VT-d, etc) so we can safely
> move flush_write_buffers() in asm-generic/dma-mapping-common.h to
> arch/x86/kernel/pci-nommu.c.
>
> The further discussion is:
>
> http://lkml.org/lkml/2009/6/28/104
>
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> Acked-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>

Ping?

> ---
> arch/x86/kernel/pci-nommu.c | 27 ++++++++++++++++++++++-----
> include/asm-generic/dma-mapping-common.h | 6 ------
> 2 files changed, 22 insertions(+), 11 deletions(-)
>
> diff --git a/arch/x86/kernel/pci-nommu.c b/arch/x86/kernel/pci-nommu.c
> index 71d412a..f7eb967 100644
> --- a/arch/x86/kernel/pci-nommu.c
> +++ b/arch/x86/kernel/pci-nommu.c
> @@ -79,12 +79,29 @@ static void nommu_free_coherent(struct device *dev, size_t size, void *vaddr,
> free_pages((unsigned long)vaddr, get_order(size));
> }
>
> +static void nommu_sync_single_for_device(struct device *dev,
> + dma_addr_t addr, size_t size,
> + enum dma_data_direction dir)
> +{
> + flush_write_buffers();
> +}
> +
> +
> +static void nommu_sync_sg_for_device(struct device *dev,
> + struct scatterlist *sg, int nelems,
> + enum dma_data_direction dir)
> +{
> + flush_write_buffers();
> +}
> +
> struct dma_map_ops nommu_dma_ops = {
> - .alloc_coherent = dma_generic_alloc_coherent,
> - .free_coherent = nommu_free_coherent,
> - .map_sg = nommu_map_sg,
> - .map_page = nommu_map_page,
> - .is_phys = 1,
> + .alloc_coherent = dma_generic_alloc_coherent,
> + .free_coherent = nommu_free_coherent,
> + .map_sg = nommu_map_sg,
> + .map_page = nommu_map_page,
> + .sync_single_for_device = nommu_sync_single_for_device,
> + .sync_sg_for_device = nommu_sync_sg_for_device,
> + .is_phys = 1,
> };
>
> void __init no_iommu_init(void)
> diff --git a/include/asm-generic/dma-mapping-common.h b/include/asm-generic/dma-mapping-common.h
> index 5406a60..e694263 100644
> --- a/include/asm-generic/dma-mapping-common.h
> +++ b/include/asm-generic/dma-mapping-common.h
> @@ -103,7 +103,6 @@ static inline void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr,
> if (ops->sync_single_for_cpu)
> ops->sync_single_for_cpu(dev, addr, size, dir);
> debug_dma_sync_single_for_cpu(dev, addr, size, dir);
> - flush_write_buffers();
> }
>
> static inline void dma_sync_single_for_device(struct device *dev,
> @@ -116,7 +115,6 @@ static inline void dma_sync_single_for_device(struct device *dev,
> if (ops->sync_single_for_device)
> ops->sync_single_for_device(dev, addr, size, dir);
> debug_dma_sync_single_for_device(dev, addr, size, dir);
> - flush_write_buffers();
> }
>
> static inline void dma_sync_single_range_for_cpu(struct device *dev,
> @@ -132,7 +130,6 @@ static inline void dma_sync_single_range_for_cpu(struct device *dev,
> ops->sync_single_range_for_cpu(dev, addr, offset, size, dir);
> debug_dma_sync_single_range_for_cpu(dev, addr, offset, size, dir);
>
> - flush_write_buffers();
> } else
> dma_sync_single_for_cpu(dev, addr, size, dir);
> }
> @@ -150,7 +147,6 @@ static inline void dma_sync_single_range_for_device(struct device *dev,
> ops->sync_single_range_for_device(dev, addr, offset, size, dir);
> debug_dma_sync_single_range_for_device(dev, addr, offset, size, dir);
>
> - flush_write_buffers();
> } else
> dma_sync_single_for_device(dev, addr, size, dir);
> }
> @@ -165,7 +161,6 @@ dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
> if (ops->sync_sg_for_cpu)
> ops->sync_sg_for_cpu(dev, sg, nelems, dir);
> debug_dma_sync_sg_for_cpu(dev, sg, nelems, dir);
> - flush_write_buffers();
> }
>
> static inline void
> @@ -179,7 +174,6 @@ dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
> ops->sync_sg_for_device(dev, sg, nelems, dir);
> debug_dma_sync_sg_for_device(dev, sg, nelems, dir);
>
> - flush_write_buffers();
> }
>
> #define dma_map_single(d, a, s, r) dma_map_single_attrs(d, a, s, r, NULL)
> --
> 1.6.0.6
>
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